As Big Bang Theory star Kaley Cuoco gets ready to walk down the aisle again, she's reflecting on what went wrong the first time she said, "I do."

In an interview with Cosmopolitan, which has her as their April cover star, Cuoco said that her ex, tennis player Ryan Sweeting, "completely changed" after the two wed. (Which sounds like it probably was a worse offense than being a bad tipper, as one of her mystery exes was.)

“I honestly thought I wouldn’t get married again. My ex ruined that word for me," she said. "I married someone the first time who completely changed. The person I ended up with was not the person I originally met."

In 2000, Cuoco, right, played 'Brady Bunch' actress Maureen McCormick in 2000's 'Growing Up Brady,' a TV movie about life behind the scenes of the classic sitcom. It co-starred a pre-'O.C.', Adam Brody, as Barry Williams and Caitlin Cullum as Eve Plumb. Her other early credits include 'Northern Exposure' and 'Ellen,' the '90s sitcom starring Ellen DeGeneres.
GARY NULL, NBC

Originally titled '8 Simple Rules for Dating My Daughter,' the series focused on Ritter's character, Paul Hennessy, a stay-at-home dad whose wife just went back to work. But Ritter died on Sept. 11, 2003, as the show was in production for its second season. The show was canceled in 2005, after its third.
GALE M. ADLER, BC

'8 Simple Rules' wrote the death of Ritter into its storyline, killing off his character, Paul Hennessy, too. Here, Cuoco, right, poses with the rest of the cast while rehearsing for an episode addressing his sudden offscreen death. (From left: Amy Davidson, Katey Sagal, James Garner, Martin Spanjers and Cuoco.)
Dan MacMedan, USA TODAY

On Sept. 24, 2007, Cuoco debuted as Penny, the female lead in CBS' 'The Big Bang Theory.' Her character, the next-door neighbor of physicists Sheldon Cooper (Jim Parsons) and Leonard Hofstadter (Johnny Galecki), was not in the original pilot. The guys experts on quantum physics, but when it comes to dealing with everyday life on earth, they're lost in the cosmos. Then they meet their sexy new neighbor, Penny.
ROBERT VOETS, CBS

The awkward courtship of Leonard and Penny put the relationship in what would evolve into a relationship comedy. It was love at first sight for Leonard but he wouldn't officially get the girl until the beginning of 'Big Bang's third season. It was a different story offscreen: The couple managed to date quietly for the first two years of the show, with no one the wiser until they broke up.
Sonja Flemming, CBS

The 'Big Bang Theory' earned its first Emmy nominations in 2009 following its second season. Here, Kaley Cuoco and co-stars Jim Parsons and Johnny Galecki appear onstage as presenters at that year's telecast.
ROBERT HANASHIRO, USA TODAY

The more time Penny spent around the boys on 'Big Bang,' the more science and nerd trivia knowledge she began to accumulate. In Season 4, they recruited her for their Justice League team Halloween costume.
CLIFF LIPSON, CBS

Season 4 also brought more gender parity to 'Big Bang': Mayim Bialik, center, and Melissa Rauch, second right, who play the love interests for Sheldon and Wolowitz (Simon Helberg, right), respectively, were promoted to series regulars.
Monty Brinton, AP

In addition to a steadily increasing salary from her day job, Cuoco began to rake in endorsement cash. She served as a pitchwoman for Priceline and Toyota. Here, she appears in the carmaker's 2013 Super Bowl spot.
Toyota

She arrived at the 2014 People's Choice Awards with a rock on her left ring finger and left carrying another: the Poeple's Choice Award for favorite comedic TV actress. Soon, she was going by Kaley Cuoco-Sweeting professionally.
Frazer Harrison, Getty Images

In the summer of 2014, Cuoco, Parsons and Galecki graduated to 'Friends' money, earning $1 million per episode, while Simon Helberg and Kunal Nayyar got bumped up to $750,000 per episode. Three years later, all five gave back some of that money, taking a voluntary paycut so co-stars Mayim Bialik and Melissa Rauch could each be paid $500,000 per episode.
Michael Yarish, CBS

In 'The Wedding Ringer, Cuoco starred as the future bride to Josh Gad's character, who had to rent a best man (Kevin Hart). The trio posed with then-Sony Pictures boss Amy Pascal at the movie's January 2015 premiere in Los Angeles.
Alberto E. Rodriguez, Getty Images

'Big Bang' fans had already met Penny's dad (Keith Carradine) in a previous episode, but the second wedding introduced us to her mom (Katey Sagal, who also played her mom on '8 Simple Rules').
Monty Brinton, Monty Brinton, CBS

A decade after 'Big Bang' changed both their lives, former real-life couple Galecki and Cuoco remain close friends. Here, they pose at a party in January 2017.
Matt Winkelmeyer, Getty Images for Entertainment Weekly

By the spring of 2016, Cuoco, a longtime horsewoman, was dating professional equestrian Karl Cook. By the end of the year, he was hitting the red carpet with her at events like December's Critics Choice Awards.
Jordan Strauss, Jordan Strauss/Invision/AP

Cuoco and Sweeting married in December 2013, just three months after they began dating. Cuoco shared a number of romantic shots with Sweeting on her Instagram, ahead of their announced split in September 2015, when her social media was scrubbed of Sweeting.

The actress got engaged to equestrian Karl Cook in November 2017 after nearly two years of dating and several months of Instagram PDA.

Cuoco told Cosmo, "I knew how much I had to give and how much I wanted to receive (after my first wedding). I knew I just had to be patient…I had to go through a lot of things, but it brought me to Karl.”